Heat transfer in trickle bed column with constant and modulated feed temperature: Experiments and modeling

Heat transfer was investigated in an insulated packed bed column with co-current downflow of gas and liquid under constant and periodically modulated gas–liquid feed temperature. Bed temperatures at three axial positions were assessed at steady state for different insulating systems, different gas and liquid flow rates and system pressure. The experimental profiles recorded were modeled with a dynamic pseudo-homogeneous one parameter model to analyze the effect of operating conditions and to deduce coefficients of overall (U) and bed to wall (h_W) heat transfer. It appears that the heat transfer is strongly affected by the system pressure, whereas the liquid flow rate has a smaller influence. The experimental data of h_W were correlated with the operating conditions leading to a small average error of 7% in the correlation. Condensation of water vapor occurring in the column seems to contribute to the heat transfer inside the packed bed. Several dynamic experiments modulating the feed temperature were also conducted and described with the help of the dynamic model. Predictions with the fitted values of U were in good agreement with experiments and give confidence to apply this model in the investigation of the catalytic wet air oxidation of phenol over carbon conducted in a trickle bed reactor under temperature feed modulation.     

The Discovery of Phenylbenzamide Derivatives as Grb7‐Based Antitumor Agents

Grb7 is a non‐catalytic protein, the overexpression of which has been associated with the proliferative and migratory potentials of cancer cells. Virtual screening strategies involving a shape‐based similarity search, molecular docking, and 2D‐similarity searches complemented by experimental binding studies (Thermofluor and isothermal titration calorimetry) resulted in the identification of nine novel phenylbenzamide‐based antagonists of the Grb7 SH2 domain. Moderate binding affinities were observed, ranging from K_d=32.3 μM for lead phenylbenzamide NSC 104999 ( 1 ) to K_d=1.1 μM for a structurally related compound, NSC 57148 ( 2 ). Deconvolution of the affinity data into its components revealed differences in lead binding, from being entropy based (lead 1 ) to enthalpically driven (NSC 100874 ( 3 ), NSC 55158 ( 4 ), and compound 2 ). Finally, the lead compound 1 was found to decrease the growth of MDA‐MB‐468 breast cancer cells, with an IC₅₀ value of 39.9 μM . It is expected that these structures will serve as novel leads in the development of Grb7‐based anticancer therapeutics.     

Current and residual effects of compost and inorganic fertilizer on wheat and soil chemical properties

Restoring soil fertility in smallholder farming systems is essential to sustain crop production. An experiment was conducted in 2011 and 2012 to study the effect of compost and inorganic fertilizer application on soil chemical properties and wheat yield in northwest Ethiopia. Full factorial combinations of four levels of compost (0, 4, 6, 8 t ha^?1) and three levels of inorganic fertilizers (0–0, 17.3–5, 34.5–10 kg N–P ha^?1) were compared in a randomized complete block design with three replications. In 2012, two sets of trials were conducted: one was the repetition of the 2011 experiment on a new experimental plot and the second was a residual effect study conducted on the experimental plots of 2011. Results showed that in the year of application, applying 6 t compost ha^?1 with 34.5–10 kg N–P ha^?1 gave the highest significant grain yield. In the residual effect trial, 8 t compost ha^?1 with 34.5–10 kg N–P ha^?1 gave 271 % increase over the control. Grain protein content increased 21 and 16 % in the current and residual effect trials, respectively, when 8 t compost ha^?1 was applied; it increased 11 and 14 % in the current and residual effect trials, respectively, when 34.5–10 kg N–P ha^?1 was applied. Under the current and residual effects of 8 t compost ha^?1, SOM increased 108 and 104 %; available P 162 and 173 %; exchangeable Ca 16.7 and 17.4 %; and CEC 15.4 and 17.1 %, respectively. Applying 6 t compost ha^?1 with 34.5–10 kg N–P ha^?1 is economically profitable with 844 % MRR.     

Decoupling Interfacial Reactions at Anode and Cathode by Combining Online Electrochemical Mass Spectroscopy with Anode-Free Li-Metal Battery

It is essential to decouple the interfacial reactions taking place at the anode and cathode in rechargeable batteries. However, due to the reactive nature of Li, it is challenging to use Li-metal batteries (LMBs) protocol to decouple the interfacial reactions. The by-products from the anode or cathode become mixed in Li/NMC111 cells, which make decoupling interfacial reactions difficult. Here, reactions at electrodes are successfully decoupled and demystified using a protocol combining anode-free LMB (AFLMB) with online electrochemical mass spectroscopy. LiPF₆ in ethylene carbonate (EC)/diethyl carbonate (DEC) and EC/ethyl methyl carbonate (1:1 v/v%) electrolytes are used to compare interfacial reactions in Li/NMC111 and Cu/NMC111 cells. In Cu/NMC111, the evolution of CO₂, CO, and C₂H₄ gases at the initial stage of first charging is due to interfacial reactions at Cu surface due to solid–electrolyte-interphase formation. However, the evolution of CO₂ and CO gases at high voltage in the entire cycles is associated with chemical and/or electrochemical electrolyte oxidation at the cathode. This work paves a new concept to decouple interfacial reactions at electrodes for developing electrochemically stable electrolytes to improve the performance with the long-cycling life of AFLMBs and LMBs.     

Ethiopian sign language recognition using deep convolutional neural network

Multimedia Tools and Applications - In recent years, several technologies have been utilized to bridge the communication gap between persons who have hearing or speaking impairments and those who...     

Infrared laser‐ignited horizontal frontal polymerization of versatile unsaturated polyester resins

Infrared laser‐ignited horizontal frontal polymerization is applied for the synthesis of unsaturated polyester resin (UPER) by copolymerizing unsaturated polyester with styrene (St), methyl methacrylate (MMA), and 2‐dimethylamino ethyl methacrylate (DMAEMA) monomers. Dependence of frontal velocity and temperature on the initiator and monomer concentration is discussed for St‐based UPER. These resins have also been characterized by Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. The results reveal St‐based resins have superior crosslinked networks. Besides, the thermo‐pH responsiveness behaviors of DMAEMA‐based resins are demonstrated by swelling measurements under the conditions of different temperatures and pH values. Moreover, by introducing CdSe@ZnS quantum dots and CsPbBr₃ perovskites into St‐ and MMA‐based resins, respectively, we realize the in situ generation of CdSe@ZnS‐UPER and CsPbBr₃‐UPER composites with good fluorescence properties and fluorescent stability, which have potential application in optoelectronic devices such as light‐emitting diode and perovskite solar cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45935.     

Evaluation of the composition and quality of watermelon and mango juices fermented by Levilactobacillus brevis,Lacticaseibacillus casei and Pediococcus pentosaceus and subsequent simulated digestion and storage

This study evaluated the composition of watermelon and mango juices fermented by Levilactobacillus (L.) brevis, Lacticaseibacillus (La.) casei and Pediococcus (P.) pentosaceus and subsequently simulated in vitro digestion and storage (4°C for 35 days). After fermentation (24 h), the microorganisms grew (~9 log CFU mL⁻¹) and fermented watermelon (FWJ) and mango juice (FMJ) became more red and yellow, respectively. DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) free radical scavenging capacities significantly increased in L. brevis and La. casei FMJ. After in vitro digestion, all the strains except La. casei in FMJ significantly decreased (P < 0.05), and P. pentosaceus survival was 2.4 and 4.5 times higher in FWJ and FMJ, respectively, than as pure culture. After storage, cell counts remained above 7 log CFU mL⁻¹, and no changes in quality attributes, total phenolic content and antioxidant capacity were recorded in P. pentosaceus FMJ. Thus, watermelon and mango are suitable matrices for lactic acid bacteria.     

3D-QSAR and molecular docking studies on pyrazolopyrimidine derivatives as glycogen synthase kinase-3beta inhibitors

Glycogen synthase kinase-3 (GSK-3), a serine/threonine kinase, is a fascinating enzyme with diverse biological actions in intracellular signaling systems, making it an emerging target for diseases such as diabetes mellitus, cancer, chronic inflammation, bipolar disorders and Alzheimer's disease. It is important to inhibit GSK-3 selectively and the net effect of the GSK-3 inhibitors thus should be target specific, over other phylogenetically related kinases such as CDK-2. In the present work, we have carried out three-dimensional quantitative structure activity relationship (3D-QSAR) studies on novel class of pyrazolopyrimidine derivatives as GSK-3 inhibitors reported to have improved cellular activity. Docked conformation of the most active molecule in the series, which shows desirable interactions in the receptor, was taken as template for alignment of the molecules. Statistically significant CoMFA and CoMSIA models were generated using 49 molecules in training set. By applying leave-one-out (LOO) cross-validation study, r(cv)2 values of 0.53 and 0.48 for CoMFA and CoMSIA, respectively and non-cross-validated (r(ncv)2) values of 0.98 and 0.92 were obtained for CoMFA and CoMSIA models, respectively. The predictive ability of CoMFA and CoMSIA models was determined using a test set of 12 molecules which gave predictive correlation coefficients (r(pred)2) of 0.47 and 0.48, respectively, indicating good predictive power. Based upon the information derived from CoMFA and CoMSIA contour maps, we have identified some key features that explain the observed variance in the activity and have been used to design new pyrazolopyrimidine derivatives. The designed molecules showed better binding affinity in terms of estimated docking scores with respect to the already reported systems; hence suggesting that newly designed molecules can be more potent and selective towards GSK-3beta inhibition.